Are Humans and Reef Sharks Mutually Exclusive?

Over at Deep Sea News, a blog post last Monday asks whether humans and reef sharks are mutually exclusive.  The post summarizes a new paper in Conservation Biology, which “studied populations of reef sharks in the Pacific and attempted to reconstruct what the “starting” populations would have been before human activities began to affect them and before anyone thought to monitor reef shark populations.” The graph below demonstrates “the relationship between the density of sharks … and the number of humans living within 200km of the sampling site” and shows (with the exception of one outlier, highlighted by DSN), that “the relationship is heavily, heavily skewed.”

Photo Caption: This is a graph with a mysterious outlier

Notes DSN: “If this proves true then it may not be that humans are doing anything to the sharks per se, just not looking after the reef generally, and that is being reflected at the top trophic level.  However you slice it, their results are more grist to the mill that we need to be doing a better job with the conservation of both reefs and sharks, because sometimes those two things are inextricably intertwined.”